9e102 Datasheet Verified -

| Pin No. | Pin Name | I/O | Function | | :--- | :--- | :--- | :--- | | 1 | BST | I/O | Bootstrap pin for high-side gate driver. Connect a capacitor between this pin and the LX pin. | | 2 | GND | — | Ground connection. | | 3 | VIN | Input | Power supply input pin. Connect a bypass capacitor close to the pin. | | 4 | EN | Input | Enable control (active high). The IC enters standby when EN voltage is low. | | 5 | FB | Input | Feedback pin for output voltage regulation. Connects to an external resistive voltage divider. | | 6 | COMP | Input/Output | Phase compensation pin. Connects an external resistor and capacitor network to GND. | | 7 | LX | Output | Switching node connection to the external inductor. | | 8 | VCC | Output | Internal regulator output (nominally 5V). Typically bypassed to GND with a 1µF capacitor. |

The loop bandwidth is typically optimized around 22.4 kHz to manage load fluctuations efficiently. 5. Pin Configuration and Functions

The BD9E102FJ itself appears to be , as indicated on major distributor websites. However, the BD9E102FJ-GE2 variant is still listed as active by some suppliers. Engineers are advised to check ROHM’s official product lifecycle status and consider the BD9E103FJ or BD9E300EFJ series as potential alternatives if the BD9E102FJ is unavailable.

A crucial aspect of the is its pin architecture. Proper pin identification prevents catastrophic chip failures during board level re-work or system integration: 9e102 datasheet

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Careful attention to PCB layout is required: the input capacitors should be placed as close as possible to the VIN and GND pins to minimize parasitic inductance, and the feedback (FB) trace should be routed away from the SW node to prevent noise coupling.

Many microcontroller datasheets (e.g., ATmega328P, STM32) require a 12-22 pF load capacitor for 16 MHz crystals. The 9E102 is for that role. However, it is used in parallel with a crystal as a DC blocking capacitor in Pierce oscillators for low-frequency crystals (32.768 kHz). Verify with your MCU’s datasheet. | Pin No

: Housed in an SOP-J8 package , which is compact but requires precise handling and soldering—ideally using a preheated hot air station to avoid damaging nearby sensitive components like capacitors or traces. 9E102 SOP-8 | In Stock - utsource

Note: The results also mentioned "AH09E102M" by Meritek, which are Ceramic Y Capacitors, which is a different component. Ensure you are referencing the ROHM part number BD9E102FJ if searching for a buck regulator. | | 2 | GND | — | Ground connection

-40°C to +125°C (Automotive or Industrial grade).

Internal regulator output pin; requires a local ceramic decoupling capacitor. Hardware Implementation & Circuit Design Guidelines

Operates at a fixed switching frequency, typically between 484 kHz and 656 kHz, which helps balance component size and efficiency.